Simulation of heat-transfer processes and assessment of the viscoplastic parameters of iron ore in blast furnaces

Stages in the development of an information and simulation system for assessing the position and shape of the viscoplastic iron-ore zone (the cohesion zone) in the blast furnace are outlined. This system also permits diagnostics of the zone's optimal configuration on the basis of available operational information for the furnace in the baseline period. In addition, the system proves useful during the design period, with variation in the smelting parameters. The capabilities of the corresponding software are discussed, and its use in blast-furnace control at OAO Magnitogorskii Metallurgicheskii Kombinat is demonstrated. © 2013 Allerton Press, Inc

Secure pseudo-random linear binary sequences generators based on arithmetic polynoms

We present a new approach to constructing of pseudo-random binary sequences (PRS) generators for the purpose of cryptographic data protection, secured from the perpetrator's attacks, caused by generation of masses of hardware errors and faults. The new method is based on use of linear polynomial arithmetic for the realization of systems of boolean characteristic functions of PRS' generators. "Arithmetizatio" of systems of logic formulas has allowed to apply mathematical apparatus of residue systems for multisequencing of the process of PRS generation and organizing control of computing errors, caused by hardware faults. This has guaranteed high security of PRS generator's functioning and, consequently, security of tools for cryptographic data protection based on those PRSs

The nature of zircon in the Volkovsky massif gabbro (Middle Urals): the age problem and geochronological consequences

The article presents new isotope-geochemical data on zircon from gabbronorites of the Volkovsky massif in the Middle Urals. The massif is a complex combination of different rock associations - from ultramafic rocks to syenites and quartz diorites, whose geological and geochronological ratios are not well-defined yet. The most widespread in the massif are gabbroids, which form three blocks - the Central, Western and Southern ones. This massif is associated with: 1) industrial deposit of copper-iron-vanadium ores and 2) gold-palladium mineralization of low sulfide type. Gabbronorites, which form peripheral parts of the gabbro blocks and in some cases form dykes among olivine gabbro, have a dual relationship with mineralization. They are host for copper-iron-vanadium type and postmineral concerning the gold-palladium mineralization localized in ultramafic rocks and olivine gabbro of the Southern block. The comprehensive study of zircon (its morphology, internal structure, U-Pb age, and silicate inclusions) has shown that in gabbronorites of the Volkovsky massif, zircon aged 427.5 ± 5.3 Ma and 428 ± 7 Ma, extracted from two different samples, contains the same set of polymineral inclusions, alien to the hosting rocks. The composition of inclusions (plagioclase ( An21), biotite (f = 0.49-0.56), quartz and apatite) corresponds to gneiss or plagiogranite. However, the zircon, according to its morphology, internal structure and age characteristics is similar to that from metamorphic rocks of the dynamothermal halo of gabbro-ultramafic bodies. This suggests that the zircon in gabbronorites of the Volkovsky massif could be borrowed from the surrounding metamorphic rocks, and therefore, the gabbronorite intrusion occurred when high-temperature metamorphic rocks of the dynamothermal halo had already existed and might have undergone anatexis and retrogressive metamorphism of amphibolite facies. The zircon age (≈427 Ma) limits the lower time limit of the formation of gabbronorite intersecting olivine gabbro of the Volkovsky massif, and may be close to the time of the formation of copper-iron-vanadium and gold-palladium mineralization type controlled by the reaction processes between gabbronorites and olivine gabbro

АНАЛИЗ МЕТОДОВ УПРАВЛЕНИЯ СВЕТОДИОДНОЙ ПОДСВЕТКОЙ ДИСПЛЕЙНЫХ УСТРОЙСТВ

The analysis of control methods for LED backlighting of display devices is carried out. An analysis of the perception of pulsed light sources by human vision is given. Recommendations are given for choosing the frequency of LED-backlighting, information of visible flickering to the minimum level, the use of a direct current of LED power supply. A combined driver for powering the LED backlight is developed.Проведен анализ методов управления светодиодной подсветкой дисплейных устройств.  Дан анализ восприятия импульсных источников света человеческим зрением. Выданы рекомендации для выбора частоты LED-подсветки, сведения видимых мельканий до минимального уровня, использования постоянного тока питания светодиодов. Разработан комбинированный драйвер для питания LED-подсветки

МИНИМИЗАЦИЯ МЕРЦАНИЙ ИМПУЛЬСНО-МОДУЛИРОВАННОЙ ПОДСВЕТКИ В ПРОЕКЦИОННЫХ СИСТЕМАХ НА МИКРОДИСПЛЕЯХ ОТРАЖАТЕЛЬНОГО ТИПА

The effect of pulsed LED light sources, widely used for illumination in projection optical indicator systems on perception of human vision, is analyzed. An analysis of the impulse signal of reflectors illumination has been carried out. Modeling and analysis of flickerings of a binary pulse-code modulated signal has been performed. Recommendations for reducing of visible flickering of the LED backlight up to the minimum level have been given.Проведен анализ влияния мерцаний импульсных светодиодных источников света, широко применяемых для подсветки в проекционных оптических системах индикации на восприятие человеческим зрением. Проведен анализ импульсного сигнала подсветки микродисплеев отражательного типа. Осуществлено моделирование и анализ мерцаний бинарного импульсно-кодового модулированного сигнала. Выданы рекомендации для сведения видимых мерцаний до минимального уровня

Fine structure of near-band-edge photoluminescence in He+-irradiated GaN grown on SiC

The effect of He ion implantation on the optical properties of epitaxial GaN-on-SiC was studied. We observed that He + irradiation increases the relative intensity of the “blue emission” and resistivity of GaN films and decreases the intensity of the near-band-edge photoluminescence. Because the intensity of the main peak is drastically decreased, the fine structure of the near-band-edge photoluminescence in GaN after He + irradiation was observed. From a comparison of observed sharp lines with photoluminescence peaks of GaNdoped with oxygen, we conclude that oxygen can produce a complex, which is characterized by a strong localization of free carriers and a large lattice distortion. The zero-phonon line of this defect has energy close to the band-gap energy of GaN

Magneto-Acoustic Waves of Small Amplitude in Optically Thin Quasi-Isentropic Plasmas

The evolution of quasi-isentropic magnetohydrodynamic waves of small but finite amplitude in an optically thin plasma is analyzed. The plasma is assumed to be initially homogeneous, in thermal equilibrium and with a straight and homogeneous magnetic field frozen in. Depending on the particular form of the heating/cooling function, the plasma may act as a dissipative or active medium for magnetoacoustic waves, while Alfven waves are not directly affected. An evolutionary equation for fast and slow magnetoacoustic waves in the single wave limit, has been derived and solved, allowing us to analyse the wave modification by competition of weakly nonlinear and quasi-isentropic effects. It was shown that the sign of the quasi-isentropic term determines the scenario of the evolution, either dissipative or active. In the dissipative case, when the plasma is first order isentropically stable the magnetoacoustic waves are damped and the time for shock wave formation is delayed. However, in the active case when the plasma is isentropically overstable, the wave amplitude grows, the strength of the shock increases and the breaking time decreases. The magnitude of the above effects depends upon the angle between the wave vector and the magnetic field. For hot (T > 10^4 K) atomic plasmas with solar abundances either in the interstellar medium or in the solar atmosphere, as well as for the cold (T < 10^3 K) ISM molecular gas, the range of temperature where the plasma is isentropically unstable and the corresponding time and length-scale for wave breaking have been found.Comment: 14 pages, 10 figures. To appear in ApJ January 200

Управление скоростью вращения роторов резиносмесителя

The paper describes technique to regulate speed of a rubber mixer that allows to improve significantly mixing quality in comparison with a control rubber mixer method without speed regulation. A mathematical model of a rubber mixer and an iterative methodology for calculation of computer control are contained in the paper. The paper gives graphic description of the system operation.Описана методика регулирования скорости резиносмесителя, которая позволяет значительно улучшить их качество по сравнению с нерегулируемым по скорости методом управления резиносмешением. В статье содержится математическая модель резиносмесителя, а также итерационная методика расчета управления на ЭВМ. Приведено графическое описание работы системы

ЦИРКОНЫ ИЗ ПОРОД МУРЗИНСКО-АДУЙСКОГО МЕТАМОРФИЧЕСКОГО КОМПЛЕКСА (СРЕДНИЙ УРАЛ): ГЕОХИМИЯ, ТЕРМОМЕТРИЯ, ПОЛИХРОННОСТЬ, ГЕНЕТИЧЕСКИЕ СЛЕДСТВИЯ

Transformation of the oceanic crust into the continental one in orogenic belts is an important problem in petrological studies. In the paleocontinental sector of the Urals, a key object for tracing the stages of metamorphism and investigating the origin of anatectic granites is the Murzinka-Adui metamorphic complex. We have analyzed trace elements in zircons and established their genesis, sources, crystallization conditions, and stages of metamorphic events and granite generation in this complex. Zircons compositions were determined by the LA-ICP-MS method. Temperatures were calculated from Ti contents in the zircons. We distinguish three geochemical types of zircons, which differ in the ratios of light and heavy REE, U, Th, Ti, Y and show different values of Ce- and Eu-anomalies and Zr/Hf ratios, which are indicative of different crystallization conditions, as follows. Type I: minimal total LREE content; clear negative Eu- and Ce- anomalies; features of magmatic genesis; crystallization temperatures from 629 to 782 °C. Type II: higher contents of Ti, La, and LREE; low Ce-anomaly; assumed crystallization from highly fluidized melts or solutions. Type III: low positive Eu-anomaly; high REE content; low Th/U-ratio; zircons are assumed to originate from a specific fluidized melt with a high Eu-concentration. Ancient relict zircons (2300–330 Ma) in gneisses and granites show features of magma genesis and belong to types I and II. Such grains were possibly inherited from granitoid sources with different SiO2 contents and different degrees of metamorphism. Based on the geological and petrogeochemical features and zircon geochemistry of the Murzinka-Adui complex, there are grounds to conclude that the material composing this complex was generated from the sialic crust. The main stages of metamorphism and/or granite generation, which are traceable from the changes in types and compositions of the zircons, are dated at 1639, 380–370, 330, and 276–246 Ma. Thus, transformation of the oceanic crust into the continental one was a long-term and complicated process, and, as a result, the thickness of the sialic crust is increased in the study area.Изучение процесса преобразования океанической коры в континентальную, идущего в орогенных поясах, – важный вопрос петрологии. Мурзинско-адуйский метаморфический комплекс, расположенный в палеоконтинентальном секторе Урала, является одним из ключевых объектов, где можно проследить этапы метаморфизма и сопряженного с ним анатектического гранитообразования. Цель работы – на основе анализа микроэлементного состава цирконов из гнейсов и жильных гранитов данного комплекса установить их генезис, источники, условия кристаллизации, уточнить этапность гранитообразования. Состав цирконов изучался методом LA-ICP-MS, температуры рассчитаны по содержанию титана в цирконе. Выделены три геохимических типа цирконов, различающихся соотношением легких и тяжелых РЗЭ, U, Th, Ti, Y, величинами Zr/Hf-отношения и аномалий Се и Eu, что предполагает разницу в условиях кристаллизации. Цирконы I типа содержат минимальное количество LREE, имеют ясные негативные аномалии Cе и Eu, обладают признаками магматического генезиса. Температура их кристаллизации составляет 629–782 °С. Цирконы II типа имеют более высокие содержания Ti, La, LREE, слабую аномалию Ce. Предполагается их кристаллизация из высокофлюидизированных расплавов или растворов. Цирконы III типа обладают слабой позитивной аномалией Eu, высокой суммой РЗЭ, низким Th/U-отношением и могли образоваться из особого флюидонасыщенного расплава с высокой концентрацией Eu. Древние реликтовые цирконы с широким разбросом возрастов (от 2300 до 330 млн лет) фиксируются в гнейсах и гранитах, имеют признаки магматического генезиса, соответствуя I и II типу. Они могли быть заимствованы из источников гранитоидного состава, имеющих разную основность или в разной степени преобразованных. Особенности строения мурзинско-адуйского комплекса, петрогеохимические параметры пород, геохимия цирконов указывают на сиалическую природу вещества, слагающего данный сегмент земной коры. Главные этапы метаморфизма и/или гранитообразования, которые нашли выражение в смене морфотипов и составов цирконов, отвечают 1639, 380–370, 330 и 276–246 млн лет, т.е. процесс континентализации был длительным, сложным и привел к повышенной мощности сиалической коры